Trend shows how the quality of water is changing over time. Depending on the sampling history duration, five and ten year timescales are available:

Can I trust this data?

The Cawthron Institute has worked alongside regional councils to verify the processes and methods used for data collection, laboratory analysis of samples collected, quality assurance and the statistical analysis and interpretation of the results presented.

Lake water quality is being monitored in this region. Proposed National Guidelines suggest that all councils should monitor lake water quality as part of their State of the Environment Monitoring Programmes, if lakes occur in the region.

State - Sampling

All samples were collected using approved field protocols and have been analysed in accredited laboratories.

State - Quality Assurance - Data Processing

Data at this site has had some form of data processing measures applied. Therefore, the data shown here are more robust than data with no data processing applied.

State - Quality Assurance - Quality Coding

Data shown here hasn’t had any kind of quality coding applied. Therefore, the data shown here is less robust than quality coded data.

Trend - Sampling Frequency

Samples are collected quarterly at this site. Proposed national guidelines suggest monthly sampling is required for robust trend analysis. Therefore, any trends shown here are less robust than those calculated from data collected monthly.

Phosphorus

Total Phosphorus

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State

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N/A

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Trend

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Total Phosphorus sample history at this site

Showing:

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Total Phosphorus samples for Lake Heather at centre

mg/m³

Date

What is this graph showing me?

This graph is displaying Total Phosphorus concentrations over the selected time period. You can adjust this period by changing the dropdowns. These records form the basis for the state and trend indicators displayed on the dashboard. This data is raw and has not had any methodology applied to it.

Lake ecological communities have undergone or are at high risk of a regime shift to a persistent, degraded state, due to impacts of elevated nutrients leading to excessive algal growth and/or plant growth, as well as from losing oxygen in bottom waters of deep lakes

Nitrogen

Nitrogen

State

Trend

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Total Nitrogen sample history at this site

Showing:

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Total Nitrogen samples for Lake Heather at centre

mg/m³

Date

What is this graph showing me?

This graph is displaying Total Nitrogen concentrations over the selected time period. You can adjust this period by changing the dropdowns. These records form the basis for the state and trend indicators displayed on the dashboard. This data is raw and has not had any methodology applied to it.

Lake ecological communities have undergone or are at high risk of a regime shift to a persistent, degraded state, due to impacts of elevated nutrients leading to excessive algal growth and/or plant growth, as well as from losing oxygen in bottom waters of deep lakes

Nitrogen

State

Trend

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Ammonia sample history at this site

Showing:

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Ammonia samples for Lake Heather at centre

mg NH4-N/l

Date

What is this graph showing me?

This graph is displaying Ammoniacal Nitrogen concentrations over the selected time period. You can adjust this period by changing the dropdowns. These records form the basis for the state and trend indicators displayed on the dashboard. This data is raw and has not had any methodology applied to it.

Lake ecological communities are moderately impacted by additional algal and plant growth arising from nutrient levels that are elevated well above natural reference conditions. Reduced water clarity is likely to affect habitat available for native macrophytes

Lake ecological communities have undergone or are at high risk of a regime shift to a persistent, degraded state (without native macrophyte/seagrass cover), due to impacts of elevated nutrients leading to excessive algal and/or plant growth, as well as from losing oxygen in bottom waters of deep lakes